GREEN THUMBS UP: Keys to growing healthy plants

Tiny flakes of pale and white pink confetti float to the earth as balmy breezes scatter the delicate blossoms of cherries and pears on a perfect Mother's Day afternoon.

Suzanne Mahler

Tiny flakes of pale and white pink confetti float to the earth as balmy breezes scatter the delicate blossoms of cherries and pears on a perfect Mother’s Day afternoon. Satin blankets of silky petals lie beneath the pewter gray branches of my magnolia trees. The flowers of these early spring-flowering trees are all too fleeting but as their lovely blossoms depart, a new wave of breath-taking color is emerging as dogwoods, crabapples, and redbuds burst into bloom. The month of May is a glorious time of year for our flowering trees and shrubs.

The consequences of our challenging winter weather are becoming more evident as the growing season progresses. Typically hardy perennials have yet to emerge, some delayed by our cool soil temperatures and recent dryness, but others unable to survive the harsh winter. Several popular shrubs, including blue hydrangeas and butterfly bushes, were particularly hard hit by the cold, their exposed stems still lifeless. Although many of these shrubs are finally sprouting new growth from the base where snow cover offered insulation, flowering will likely be delayed and some may not produce any blooms this season.

While our weather cannot be controlled, careful analysis of your property’s growing conditions and selection of plants suitable to its availability of light, drainage, and soil composition will greatly improve the viability of your plants. Even within a single landscape, a wide variety of conditions are possible: wet, dry, sun, shade, exposed, or protected. Although some of these existing conditions can be modified, to do so may require a considerable investment of time or money and plants may still succumb during years of weather extremes.

An ideal way to determine what types of plants will thrive on your given site is to identify and research the types of plants that are indigenous to your property or neighborhood. Wild trees, shrubs, weeds, and wildflowers, especially natives, which are becoming increasingly popular due to their hardiness, offer great clues about your soil type, light, and exposure, surviving year to year despite variations in moisture and temperature.

Soil composition is of primary importance when selecting plants. Soil is comprised of inorganic (mineral) components and organic (decomposed plants) matter. Clay soils are composed of tiny particles that cling together and drain slowly, holding moisture, which can lead to rot, especially during the winter months when plants are not actively growing. Sandy soils contain large particles that drain rapidly and dry out quickly, especially during dry spells and summer heat. Although the addition of compost improves all soil types, providing drainage and airflow in clay soils while enhancing water and nutrient retention in sandy soils, selecting plants that prefer your given soil conditions is often the best strategy to ensure plant longevity.

A soil’s pH is also important for plant health. Many plants cannot effectively absorb nutrients in New England’s typically acidic soils. Have your soil pH tested by a local nursery or the UMass Extension Service for an accurate determination. The ideal pH for growing the majority of plants is between pH 6.0 and pH 7.0.

The availability of light is another critical aspect in choosing plants and is best judged once trees have fully leafed out. A site that receives morning sun and afternoon shade or dappled shade most of the day is considered shady while a site that receives morning shade and afternoon sun is considered full sun. Thinning trees and removing lower limbs will often increase the availability of light to promote flowering for shade-tolerant plants as few plants flower in densely shaded areas.

Lawns and gardens require a minimum of 1 inch of water per week during the active growing season to maintain their health and vigor. Provide a deep, thorough soaking of your plantings once or twice a week to promote deeper roots systems. Superficial watering every day may cause roots to come to the surface, making plants more susceptible to drought, insects and diseases, and winter damage. When possible, water early in the day so plant foliage dries off before dark diminishing the potential for fungal diseases, slugs, and snails.

As the spring growing season progresses, take time to analyze your personal site. Knowledge of soil conditions and the availability of light will greatly assist in the selection of plants that are well suited to their growing environment ensuring healthy, attractive plants and gardens.

Suzanne Mahler is an avid gardener, photographer and lecturer who has been developing the 1.5-acre property surrounding her home in Hanover for more than 30 years. Her weekly gardening column ‘Green Thumbs Up’ has appeared in GateHouse Media New England newspapers for more than a decade. She is a member of a local garden club, past president of the New England Daylily Society, an overseer for the Massachusetts Horticultural Society and employed at a garden center.